Lowest To Highest

From below sea level to a Colorado high in a light jet

By John Hayes, Photos By Jessica Ambats

Lowest To Highest

I spent over a year making the transition from piloting a TBM 700 turboprop to becoming a jet pilot; a process that has taken me through an ATP rating, two type ratings, a lot of simulator time, a jet trip to Paris, a bit of mentoring, one or two scary moments, some frustration and piles of cash.

I started the process 17 years after soloing, with about 3,400 hours in my logbook and five years of turboprop experience. I’ve finally cleared the magic number of 100 hours of single-pilot jet time, but I’m not quite ready to be called a superhero. My story isn’t unusual for many GA pilots now flying the new generation of light jets. A few have even made the jump from single-engine, fixed-gear airplanes and managed the transition to qualify for single-pilot jet operations. It’s not easy, quick or cheap, but it’s possible.

This spring, I embarked on a trip in my Citation Mustang from the lowest airport in the continental United States (Furnace Creek in Death Valley, Calif., which is located 210 feet below sea level) to the highest (Lake County in Leadville, Colo., which is at an elevation of 9,927 feet). Such a trip is certainly possible in many piston airplanes (and would be easy in the TBM 700), but could it be done in a jet at a time of year when the temperatures are climbing into the triple digits? It would be a challenge for a newbie jet pilot like me, but I decided to give it a try to see what it takes to make it happen safely.

The 3,060-foot Furnace Creek runway is adjacent to the Furnace Creek Ranch and isn’t hard to spot from the air.

What’s So Different About A Jet? Operating a jet is different from operating a piston or turboprop airplane, and there’s a lot to learn in order to do it correctly. One of the first lessons is that virtually all operations are done IFR. Operating any jet below FL180 limits range, speed and economy—it just isn’t done. The second lesson is that nothing is improvised. One of the leading types of jet accidents involves running off the end of the runway on landing. Speeds must be carefully computed for each landing to take into account weight, temperature, aircraft configuration and runway requirements.

Keep in mind that jets are slippery and the engines can take seven to 10 seconds to spool up, so speed adjustments take time. The small throttle adjustments that a piston pilot might make to adjust speed have almost no immediate effect in a jet. It isn’t uncommon to pull the power to idle to get a jet to slow down; at the other extreme, full power can quickly get a jet out of an impending stall with little need to actually lower the nose. One other thing about jet power: Thrust is heavily dependent on altitude and temperature—unlike in turbocharged piston engines.

All of this makes sense if you understand that unlike early jets, modern high-bypass jet engines generate thrust by accelerating a large volume of air through a relatively small change in velocity. Modern engines produce the most thrust when the air is cold and dense. In warmer weather, thrust is noticeably decreased so that acceleration, climb rate and cruise speed go way down. This loss of thrust in hot weather is particularly noticeable for the small engines powering the new wave of light jets, since these airplanes aren’t as overpowered as many larger jets.

This leads to another issue that takes many jet newbies by surprise: It’s necessary to compute speeds, runway requirements and climb performance for nearly every takeoff—particularly when the weather gets hot. In the summer, it’s not always possible to safely take off out of many airports with enough fuel to go very far. When it gets hot, even a small runway gradient can make a huge difference in takeoff performance.

Jetting To Death Valley The Furnace Creek Airport in Death Valley, Calif., is 210 feet below sea level. From the air, the 3,000-foot runway looks awfully short, and legend has it that the surrounding desert is littered with the remains of military jet planes whose pilots tried to maneuver below sea level. As we circle the airport, I carefully look for the wind indicator to make sure that I’m landing into the wind—even a light tailwind could push the aircraft off the end of this runway. Temperatures at the airport are hovering around 100 degrees F, and there’s no jet fuel or service on the ground.

Before departing for Death Valley, my copilot and I carefully considered the fuel requirements to make the next fuel stop and how much runway we’d need to land and take off again at our expected weight and temperature. Fortunately, North Las Vegas Airport is only 83 miles to the east, so we won’t need much fuel to safely make it there with plenty of reserve. With a light load, the Mustang performance software shows a landing distance of about 2,300 feet, so if we touch down on the first 500 feet of runway, then we should have enough length. Clearly, there’s not a lot of room for error.

The Lowest: Death Valley, Calif., 210 Feet Below Sea Level

The runway at Furnace Creek is at 210 feet below sea level. The large parking ramp is next to the National Park Service horse/mule corral and can handle a large number of planes. The airport is unmanned, but 100LL fuel is available on call, and rides to the Furnace Creek Inn & Ranch can be arranged from a local phone in a sparse flight-planning room with a restroom. The approach to the airport is surrounded by numerous military operation areas and restricted zones, so it’s not uncommon to see exotic aircraft operating in the skies overhead.

The Furnace Creek Inn & Ranch (www.furnacecreekresort.com) is a four-diamond resort set in a palm-covered oasis in the desert. It has an 18-hole golf course, a large spring-fed swimming pool, tennis courts, four restaurants and a borax museum. The decor is “elegant 1930s” with numerous portraits of Death Valley luminaries, miners and characters lining the halls. Views of the surrounding desert are incredible. The ranch is open year-round, and the inn operates from mid-October through mid-May.

At 500 feet on final approach, the airspeed is five knots fast and slowing, so I call “stable.” At 50 feet, we’re right on speed so I close the throttles, and the wheels settle gently to the runway. I quickly pull the speed brakes and with firm braking, the aircraft stops about 2,500 feet down the runway. The next challenge is turning around: The runway is only 70 feet wide so it takes a little differential power and braking to pivot the airplane in a tight circle. Not hard, but dropping a wheel into the soft shoulder could well mean a stuck airplane at a deserted airport—not a good idea.

The next morning dawns cool, but the temperature will rise quickly to an expected high well above 100 degrees F by midday. The Mustang performance calculator shows that at a weight of 7,400 pounds, the aircraft must depart before the OAT hits 90 degrees F, or the runway will be too short for a safe departure. Cessna determines the runway requirement by the longest of: 1) the distance required to reach the decision speed (V1), lose an engine and stop; 2) the distance required to reach V1, continue the takeoff on one engine and reach 35 feet; or 3) the ground roll required to lift off with two engines times 1.15. At 90 degrees F, we’ll need 2,650 feet to meet the longest of those requirements at Furnace Creek. Any thought of taking off from here on a hot day with enough fuel to go very far simply isn’t realistic. At this time of year, we clearly can’t make it safely to Leadville without a stop in Las Vegas for fuel.

With the temperature climbing through about 85 degrees F, we taxi to the end of the runway, hold the brakes, work the throttles up to maximum thrust and release the brakes. It may be a light jet, but at light weight and maximum thrust, the Mustang really pushes you back in the seat. We’re off the runway in about 2,500 feet, climbing safely to altitude for a quick fuel stop before facing the next challenge—flying to the highest airport in the continental United States.

The Highest: Leadville, Colo., 9,927 Feet

The city of Leadville has a rich mining history and, at an elevation of 10,152 feet, is the highest incorporated city in North America. It’s surrounded by some of Colorado’s highest peaks—including Mt. Massive and Mt. Elbert (both are more than 14,400 feet tall)—and offers abundant opportunities for outdoor activities.

Leadville Airport (www.leadville airport.com) is run by the county; Debbie Benson is the airport manager. A crew car is available for a quick ride into town; rental cars have to be delivered from another town 75 miles away and may be quite expensive.

Views from the airport are spectacular, and visitors should expect changeable mountain weather. The ride into the picturesque town is well worth it—there are several good restaurants, six museums, and walking and driving tours of historical sites. Pilots landing at Leadville will receive a certificate documenting their arrival at the highest airport in the continental United States. Because of its elevation, Leadville is frequented by flight crews working on high-altitude certification projects.

Leadville—Hot, High & Spectacular At an elevation of 9,927 feet, Leadville is a little more challenging to fly into. The weather isn’t perfect, and it looks like we’ll have to fly an approach through some juicy-looking buildups with forecasted icing. The GPS approach to runway 16 starts at 14,000 feet with a minimum decent altitude of 1,432 feet above the runway. Fortunately, the weather is reported to be above minimums, so a landing seems likely. As the aircraft descends, sure enough, moderate rime ice starts to build on the way to the initial approach fix. Fortunately, the NEXRAD weather display shows that we’ll be turning away from the major returns when we make a 90-degree turn to start the approach. On the approach and about three miles from the airport, the ice is gone and we break out to the sight of runway 16 on the nose. The winds favor runway 34, so we fight moderate turbulence to circle to land. At 50 feet, the sensation of speed is hard to ignore, and the plane touches down with a satisfying chirp.

The flight into Leadville involved moderate rime icing in the clouds. Fortunately, NEXRAD showed that we would be turning toward better conditions on the GPS approach.

The Cessna charts correctly predicted that the landing would be no problem, but taking off again will be another story. As in Death Valley, we need enough runway to get airborne, but here in the mountains, we also need to consider the required climb gradient on departure in case we lose an engine. In a single, if the engine conks out, you’re going down; in a twin jet, however, you train to keep going. For the new generation of light jets, this can cause some very real limitations for operations out of many airports—particularly in the summertime. With afternoon temperatures predicted in the high 50s, our charts show that we can’t depart until early the next morning when it’ll dawn a little below freezing; otherwise, we may have little or no climb performance if we lose an engine.

There are two kinds of instrument procedures that may affect our departure. The standard instrument departure (SID) typically requires a standard rate of climb of at least 200 feet per nm, unless otherwise noted. To accept an SID, the pilot must ensure that the airplane can maintain the required climb gradient—that’s almost never a problem with both engines running. It’s a good idea to check that the climb gradient can also be maintained on one engine. Note, however, that the loss of an engine would be an emergency so it’d be possible to deviate from the procedure should that happen.

The second kind of departure is an obstacle clearance departure (OCD), which is what we have out of Leadville. The OCD provides the route and climb gradient needed to safely clear terrain. ATC normally won’t assign the OCD out of uncontrolled airports like Leadville, but it’d be foolhardy to depart IFR in the clouds or at night and not follow the OCD. This is more than the legal requirement of an SID—you simply don’t want to depart into weather, lose an engine and not be able to stay out of the rocks. Leadville has an OCD for each runway direction, with different climb gradients, so a careful review of each procedure is required before departure.

Of course, if the weather is clear, the departure can be made VFR. To be safe, the trick is to verify that the airplane is light enough to maintain a safe climb gradient on one engine, even if it may not meet the requirements of the OCD procedure. Leadville is at one end of a broad valley that drops in elevation to the south. With only 1,200 pounds of fuel on board and a temperature right around freezing, the Mustang can climb at well over 300 feet per nm on one engine, so it’s very close to meeting the most restrictive OCD procedure out of Leadville.

By departing VFR, we can easily follow the valley as it drops to the south if we lose an engine on climb out. With both engines running, we’ll quickly climb above the terrain where we can pick up our instrument clearance and head to a nearby fuel stop. One other thing we do is take off with zero flaps to ensure that we have extra speed before rotation. Then, if an engine fails at the worst moment, there’s plenty of airspeed to manage a continuous climb. Our charts show that the required field length with zero flaps will be right around 3,700 feet, and since the runway is 6,400 feet long, we should have plenty of pavement to get airborne.

We arrive at the airport at 5:30 a.m. under clear skies and with a temperature of 33 degrees F, so we quickly prepare for departure. At full power, the engines are running fine, but the takeoff roll feels sluggish. For good measure, I hold the plane on the pavement until we’re about 10 knots fast. On rotation, the plane feels mushy, and it seems like we’re barely 50 feet in the air as the end of the runway disappears below. Both engines continue to work perfectly as we rapidly gain speed and climb briskly to 16,500 feet, where we pick up our clearance to Montrose to take on more fuel for our final leg home. The views of the snow-capped Rocky Mountains are spectacular as we climb into the flight levels.

Being a newbie to hot and high jet flying, I was pretty conservative about weight limits for both airports, but that’s probably a good idea for everyone going into either of these two locations in any kind of airplane. The Citation Mustang handled the mission well, and in my mind, it was the real superhero.

John Hayes is a retired entrepreneur with a Ph.D. in optical engineering. He has owned numerous airplanes including an Extra 300, a TBM 700 and a Citation Mustang. He was a founder and past president of the TBMOPA, and is a founder and current president of the Citation Jet Pilots owner-pilot association. He has an ATP rating and nearly 3,500 hours.

Jet Operations

Most of the thrust from a modern high-bypass turbofan comes from the large amount of air driven by the ducted fan in the front of the engine. The fan acts much like a high-speed propeller, pulling cool air around the hot core exhaust to make the engine more efficient and much quieter than a pure jet engine. A high-pressure compressor provides pressurized air to the burner, where fuel is ignited, providing hot exhaust to drive both the high-pressure compressor and fan turbines.

Total thrust is determined by the mass of air that can be accelerated through the engine. So, like normally aspirated piston engines, turbofan engines lose thrust as the density of air goes down. That loss of thrust is quite noticeable during a climb and when ambient temperatures go up. For this reason, jet pilots should pay special attention to takeoff capabilities when the temperature goes up—particularly at high altitude.